Tank system for explosion prevention area

Abstract

To provide a tank system for an explosion prevention area that can be warmed up in the explosion prevention area.SOLUTION: A tank system for an explosion prevention area comprises a tank 20 which is installed in the explosion prevention area 2, a jacket which is provided in the outer periphery of the tank 20 and in which a heat medium circulates, and an electric heater 60 which heats the heat medium in the jacket, wherein the explosion prevention area 2 is set to a reference height H which is the maximum height that an inflammable gas produced in the explosion prevention area 2 and heavier than air can reach from the floor of the explosion prevention area 2, and the electric heater 60 is provided at a height larger than the reference height H. The tank system for the explosion prevention area comprises an adjuster 74 for adjusting the installation height M of the heater 60 in the height direction from the floor of the explosion prevention area 2, and a limit switch device 80 which detects the installation height M, and a controller 3 comprises a determination part which determines whether the installation height M is higher than the reference height H.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a tank system for use in an explosion-proof area. [Background technology]

[0002] In pharmaceutical manufacturing plants, processes that may generate flammable gases or vapors of flammable liquids are carried out in explosion-proof areas. In explosion-proof areas, safety measures are generally taken by not using devices powered by electricity. For example, in Patent Document 1, explosion prevention measures are taken by supplying pressurized air into a tank to discharge drainage from the tank, rather than using an electrically driven pump. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 61-011098 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 does not take into consideration heating of raw materials and the like in the tank. In view of such circumstances, the present invention has an object to provide a tank system for an explosion-proof area that can heat raw materials in an explosion-proof area. [Means for solving the problem]

[0005] An embodiment for achieving the above object is a tank system for an explosion-proof area comprising a tank device to be installed in the explosion-proof area and a control device, wherein the tank device comprises a tank to be installed in the explosion-proof area, a jacket provided around the outer periphery of the tank through which a heat transfer medium flows, an electric heater to heat the heat transfer medium in the jacket, an adjustment means for adjusting the installation height of the electric heater in the height direction relative to the floor of the explosion-proof area, and a detection means for detecting the installation height, and the control device is characterized in that the tank system for an explosion-proof area comprises a judgment unit for judging whether the installation height obtained from the detection means is higher than a reference height stored in a memory unit. [Effects of the Invention]

[0006] According to the present invention, there is provided a tank system for use in an explosion-proof area that can be heated in the explosion-proof area. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic configuration diagram of a tank system for an explosion-proof area according to a first embodiment. [Figure 2] FIG. [Figure 3] FIG. 10 is a schematic diagram illustrating the configuration of a tank system for an explosion-proof area according to a second embodiment. [Figure 4] FIG. 10 is a diagram showing the relationship between the extension of the legs and the installation height. [Figure 5] FIG. 2 is a block diagram showing the functions of a control device. [Figure 6] FIG. 1 is a schematic diagram of a tank system for explosion-proof areas when the legs are at standard length. [Figure 7] FIG. 1 is a schematic diagram of a tank system for explosion-proof areas when the legs are extended by an extension amount. [Figure 8] 10 is a display example of the touch panel 8. [Figure 9] FIG. 10 is a schematic diagram illustrating the configuration of a tank system for an explosion-proof area according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] First Embodiment 1 is a schematic diagram of a tank system for an explosion-proof area. The tank system for an explosion-proof area (hereinafter referred to as tank system) 1 of this embodiment includes an explosion-proof area 2, a control device 3, a power source 4, an air supply device 5, and a tank device 10.

[0009] The explosion-proof area 2 is a place where vaporized flammable liquid (hereinafter referred to as flammable gas) may be generated. According to regulations, the explosion-proof area 2 is a facility or area designated as a small-quantity hazardous materials handling facility. Flammable gas is a gas that is heavier than air, such as ethanol. The explosion-proof area 2 is a room equipped with a door (not shown), through which the tank device 10 can be carried in and out. As will be described later, the tank 20 of the tank device 10 stores liquid contents including ethanol, and some of the ethanol may vaporize and be released outside the tank 20 as flammable gas. If the ethanol vaporizes while the explosion-proof area 2 is sealed, it will accumulate in the lower part of the explosion-proof area 2.

[0010] The control device 3 is a device also called a programmable controller or sequencer. The control device 3 includes a CPU, a memory unit, etc., and reads and executes a control program stored in the memory unit. The control device 3 is also connected to a power source 4, and supplies power from the power source 4 to an electric heater (hereinafter referred to as heater) of the tank device 10. The control of the heater by the control device 3 will be described later. The number of control devices 3 is not limited to one, and the below-described control may be performed by multiple devices.

[0011] The air supply device 5 is a device that supplies air to the air-driven pump (hereinafter referred to as the pump) of the tank device 10, and is composed of, for example, a cylinder that holds compressed air and a pressure reducing valve that reduces the pressure of the compressed air supplied from the cylinder to a predetermined level.

[0012] There is no limit to the number of tank devices 10, control devices 3, and air supply devices 5 installed in the explosion-proof area 2. Two or more tank devices 10 may be installed. One control device 3 may control multiple tank devices 10 collectively, or multiple control devices 3 may control multiple tank devices 10 individually. One air supply device 5 may supply air to each of the multiple tank devices 10, or each of the multiple air supply devices 5 may supply air to each of the multiple tank devices 10.

[0013] 2 is a cross-sectional view of the tank device 10. The tank device 10 includes a tank 20, a jacket 30, a circulation flow path 40, a pump 50, a heater 60, and a moving means 70 (see FIG. 1).

[0014] Tank 20 includes a container 21 and a lid 22, and lid 22 is provided with an inlet 23 for introducing powdered or liquid raw materials and a solvent such as purified water or ethanol. In tank 20, both ethanol and purified water are used as solvents for dissolving the raw materials. Hereinafter, the mixture of raw materials and solvent stored in tank 20 will be referred to as the content liquid. In addition, a discharge port 24 for discharging the content liquid of container 21 is provided at the bottom of container 21. Although not specifically shown, tank 20 may be provided with a stirring device for stirring the content liquid.

[0015] The jacket 30 is a member that forms a flow path between itself and the outer periphery of the tank 20. There are no particular limitations on the shape or number of the flow paths formed by the jacket 30. The jacket 30 of this embodiment is provided around almost the entire circumference of the tank 20 at a fixed distance from the outer periphery of the tank 20.

[0016] A circulation flow path 40 that circulates the heat transfer medium together with a pump 50 is connected to the jacket 30. The circulation flow path 40 is composed of a first flow path 41 and a second flow path 42. The first flow path 41 is connected to the lower part of the jacket 30, and the second flow path 42 is connected to the upper part of the jacket 30. The first flow path 41 connects the lower part of the jacket 30 to the pump 50, and the second flow path 42 connects the upper part of the jacket 30 to the pump 50. The pump 50 sends the heat transfer medium to the jacket 30 via the first flow path 41. The heat transfer medium discharged from the jacket 30 is returned to the pump 50 via the second flow path 42.

[0017] The heater 60 is configured to heat the heat medium inside the jacket 30. Specifically, the heater 60 is a device that includes a heat generating portion 61 and a connector portion 62 to which a power source is connected, and the heat generating portion 61 generates heat when power is supplied to the connector portion 62. An opening through which the heater 60 is inserted is provided in the jacket 30, and the heater 60 is fixed in a state in which it is inserted into the opening. The heat generating portion 61 is disposed within a flow path formed by the jacket 30, and the connector portion 62 is exposed to the outside of the tank 20. A power cable 6 (see FIG. 1 ) is connected to the connector portion 62, and power is supplied from the control device 3 via the power cable 6. In this embodiment, three heaters 60 are attached to the jacket 30, but there is no particular limitation on the number.

[0018] The moving means 70 is a mechanism that supports the tank 20 and the pump 50 and is movable while supporting them. Specifically, it includes legs 71 fixed to the container 21 of the tank 20, wheels 72 attached to the tip end of the legs 71, and a substantially horizontal support plate 73 fixed to the legs 71. The wheels 72 are rotatable about an axis that is vertical to the legs 71, so that the moving means 70 can move in any direction within a horizontal plane. There are no particular limitations on the number of legs 71 or the shape of the support plate 73.

[0019] The pump 50 is a so-called air-driven pump that is driven by air supplied from the air supply device 5 via the pipe 7. The pump 50 sends the heat medium that has returned from the second flow path 42 to the jacket 30 via the first flow path 41. The pump 50 is disposed below the tank 20 and is fixed to a support plate 73 of the moving means.

[0020] The control of the heater 60 by the control device 3 is not particularly limited, but can be performed as follows. For example, a first temperature sensor that measures the temperature of the liquid contained in the tank 20 and a second temperature sensor that measures the temperature of the heat medium in the circulation flow path 40 are provided, and the control device 3 is configured to read the values ​​of the first and second temperature sensors. The control device 3 sets a target temperature of the heat medium and controls the amount of power supplied to the heater 60 so that the temperature of the heat medium measured by the second temperature sensor becomes the target temperature. The control device 3 also sets a target temperature of the liquid contained in the tank 20 and changes the target temperature of the heat medium so that the temperature of the liquid contained in the tank 20 becomes the target temperature. For example, when the temperature of the liquid contained in the tank 20 measured by the first temperature sensor is lower than the target temperature, the control device 3 increases the target temperature of the heat medium. This increases the rate at which the temperature of the liquid contained in the tank 20 rises. Then, when the temperature of the liquid contained in the tank 20 measured by the first temperature sensor approaches the target temperature, the control device 3 gradually approaches the target temperature of the heat medium to the target temperature of the liquid contained in the tank 20.

[0021] The tank system 1 including the tank device 10 is used as follows. The raw material and a solvent, such as purified water or ethanol, are weighed and placed in the tank 20 in a location other than the explosion-proof area 2, such as a liquid preparation room. The purified water is preferably heated to a temperature suitable for dissolution. The tank 20 containing the liquid is then transported to the explosion-proof area 2. In the explosion-proof area 2, the air supply device 5 and the pump 50 are connected via piping 7, and a power cable 6 is connected to the connector 62 of the heater 60. The pump 50 is then operated by supplying air from the air supply device 5. The pump 50 circulates the heat medium through the circulation flow path 40 and the flow path of the jacket 30. Meanwhile, the heater 60 is controlled by the control device 3, heating the heat medium circulating in the jacket 30 to a predetermined temperature, which then heats the liquid stored in the tank 20. While the heat medium in the tank 20 is being heated by the heater 60, some of the ethanol in the liquid may vaporize and be released into the explosion-proof area 2.

[0022] The explosion-proof area 2 is set with a reference height H, which is the maximum height that flammable gas can reach from the floor of the explosion-proof area 2. Such reference height H is estimated in advance by actual measurement or calculation. For example, the reference height H is estimated based on the maximum number of tank devices 10 that can be brought into the explosion-proof area 2, the maximum amount of ethanol contained in the liquid content of each tank device 10, and the floor area of ​​the explosion-proof area 2. The estimate may be made assuming that all or part of the maximum amount of ethanol in the tank device 10 will evaporate. Furthermore, it is not necessary to always install the maximum number of tank devices 10 in the explosion-proof area 2. The reference height H may be multiplied by a safety factor.

[0023] 1 and 2, the height of the heater 60 in the height direction relative to the floor of the explosion-proof area is referred to as the installation height. The installation height is set at a position higher than the reference height H. The pump 50 is set at a position lower than the reference height H.

[0024] As described above, the tank apparatus 10 of this embodiment is provided with a jacket 30 on the tank 20, and is capable of heating the heat transfer medium flowing through the flow path formed by the jacket 30 with the heater 60. The heater 60 generates heat electrically, but is installed on the tank 20 so that its installation height is higher than the reference height H. With this tank apparatus 10, even if flammable gas is generated in the explosion-proof area 2 and an electrical malfunction occurs in the heater 60, causing it to become an ignition source, there is no risk of the flammable gas igniting because the heater 60 is installed at a position higher than the reference height H. In this way, the tank apparatus 10 reduces the possibility of flammable gas ignition and can heat the raw materials and the like stored in the tank 20 without relying on an external heat transfer medium.

[0025] The tank apparatus 10 of this embodiment includes a circulation flow path 40 connected to the jacket 30 and an air-operated pump 50, with the pump 50 located at a position lower than the reference height H. With this tank apparatus 10, the heat transfer medium in the jacket 30 circulates through the circulation flow path 40, so the heat transfer medium can be quickly heated to a uniform temperature. Furthermore, because the pump 50 is air-driven and does not use electricity, there is no risk of igniting flammable gas even if the pump 50 is located at a position lower than the reference height H.

[0026] It is also possible to heat a heat medium outside the explosion-proof area 2, introduce the heat medium into the jacket 30 of the tank 20 inside the explosion-proof area through piping, and use the heat medium to heat raw materials, etc. In this case, there are no problems with explosion prevention measures because the device for heating the heat medium is outside the explosion-proof area, but piping must be routed from outside the explosion-proof area to inside the explosion-proof area, and installation space for the piping is required. Since the tank must be placed according to the piping inside the explosion-proof area, the installation location of the tank is fixed, and there is a lack of flexibility in tank placement. In reality, this is limited to locations close to the point of use, such as a filling machine, located downstream of the tank.

[0027] However, the tank apparatus 10 of this embodiment is equipped with a heat medium, a circulation flow path 40 for circulating the heat medium in the jacket 30, and a pump 50, so heating can be performed in the explosion-proof area 2 without relying on a heat medium from outside. This eliminates the need to run piping from outside the explosion-proof area 2 to inside the explosion-proof area 2, eliminating the need for installation space for that piping. Furthermore, since it is not necessary to position the tank apparatus 10 in accordance with the piping, flexibility in the placement of the tank apparatus 10 is improved. For example, it becomes possible to carry the tank apparatus 10, after heating has been completed in the explosion-proof area 2, to a location where a use point is located.

[0028] The tank apparatus 10 of this embodiment includes a moving means 70 that supports and moves the tank 20 and the pump 50 disposed below the tank 20. Such a tank apparatus 10 allows the tank apparatus 10 to be movable, and the moving means 70 can also be used to support the pump 50. Furthermore, since the pump 50 can be disposed in the space below the tank 20, space can be saved by the area required for installing the pump 50.

[0029] The tank system 1 of this embodiment includes a tank device 10, an explosion-proof area 2, and a control device 3 and an air supply device 5 disposed in the explosion-proof area 2. According to this tank system 1, a jacket 30 is provided on the tank 20, and a heat transfer medium flowing through a flow path formed by the jacket 30 can be heated by a heater 60. The heater 60 generates heat electrically, but is disposed at a position higher than the reference height H. Even if flammable gas is generated in the explosion-proof area 2 and an electrical malfunction occurs in the heater 60, causing it to become an ignition source, the heater 60 is disposed at a position higher than the reference height H, so there is no risk of the flammable gas igniting. In this way, the tank system 1 reduces the possibility of flammable gas ignition and can heat raw materials and the like stored in the tank 20 without relying on an external heat transfer medium.

[0030] Furthermore, since the tank system 1 of this embodiment is equipped with a heat transfer medium, a circulation flow path 40 for circulating the heat transfer medium through the jacket 30, and a pump 50, heating can be performed in the explosion-proof area without relying on a heat transfer medium from outside. This eliminates the need to run piping from outside the explosion-proof area 2 to inside the explosion-proof area 2, eliminating the need for installation space for the piping. This allows heating to be performed in a compact explosion-proof area 2, or allows a greater number of tank devices 10 to be installed within the explosion-proof area 2. Furthermore, since it is not necessary to position the tank devices 10 according to the piping, flexibility in the placement of the tank devices 10 is improved. For example, it becomes possible to transport the tank devices 10 that have completed heating in the explosion-proof area 2 to a location where a use point is located.

[0031] In the above embodiment, the air supply device 5 is arranged in the explosion-proof area 2, but the arrangement is not limited to this. The air supply device 5 may be arranged outside the explosion-proof area 2, and the piping 7 may be arranged from outside the explosion-proof area 2 to inside the explosion-proof area 2. Furthermore, the pump 50, the air supply device 5, and the piping 7 may be arranged at a position higher than the reference height H.

[0032] In the above embodiment, the circulation flow path 40 is configured so that the pump 50 causes the heat medium to circulate through the first flow path 41, the jacket 30, and the second flow path 42 in this order before returning to the pump 50, but the configuration is not limited to this. The circulation flow path 40 may also be configured so that the pump 50 causes the heat medium to circulate through the second flow path 42, the jacket 30, and the first flow path 41 in this order before returning to the pump 50.

[0033] Second Embodiment A tank system 1 for use in an explosion-proof area according to embodiment 2 will be described using Figures 3 to 7. The tank system 1 for use in an explosion-proof area according to embodiment 2 differs from embodiment 1 in that the installation height of the heater 60 is adjustable, the installation height of the heater 60 can be detected, and it is determined whether or not the height exceeds a reference height. Note that the same components as those in embodiment 1 are given the same reference numerals, and redundant explanations will be omitted.

[0034] As shown in Figures 3 and 4, the tank 20 is supported by legs 71. A screw-type adjuster 74 that can adjust the height is provided at the bottom of the legs 71. The length of the legs 71 can be extended or shortened by adjusting the amount that the adjuster 74 is screwed in. Because the legs 71 are extendable and retractable in this way, the position in the height direction of the tank 20 supported by the legs 71 can also be adjusted. The legs 71 and the adjuster 74 are an example of a support member in the claims.

[0035] The length of the leg 71 includes the length of the adjuster 74. The length of the leg 71 when it is at its shortest is the reference length. The difference between the reference length and the length of the leg 71 extended by adjusting the adjuster 74 is referred to as the extension L.

[0036] Because the heater 60 is fixed to the tank 20, the installation height of the heater 60 can be adjusted by extending or contracting the legs 71. In other words, the legs 71, which are extendable support members, and the adjuster 74 are an example of an adjustment means for adjusting the installation height of the heater 60.

[0037] Although not shown, the adjuster 74 may be provided with a scale that displays the extended length. By visually checking this scale, it is possible to grasp how much the installation height of the heater 60 can be changed.

[0038] The tank system 1 for explosion-proof areas is equipped with a limit switch 80 as a detection means for detecting the installation height. The limit switch 80 is a known device for detecting objects. The limit switch 80 is equipped with an actuator unit A that turns on a switch when the leg 71 comes into contact with the object. Such a limit switch 80 is arranged so that the actuator unit A of the limit switch 80 is activated when the leg 71 is extended by adjusting the adjuster 74.

[0039] Specifically, two limit switch devices 80 are provided on a support column 75 extending from a support plate 73. The limit switch devices 80 are arranged at different heights. The actuator units A of the limit switch devices 80 are referred to as actuator unit A1, actuator unit A2, and so on, from the lowest to the highest. With this arrangement, the actuator units A1 and A2 each operate in accordance with the extension L of the leg 71. The number of limit switch devices 80 is not limited to two.

[0040] The limit switch device 80 and the control device 3 can communicate with each other via wire or wirelessly. When the leg 71 extends and operates the actuator unit A, the limit switch device 80 turns on, and the on signal is sent to the control device 3. The on signal and the extension amount L when the actuator unit A1 and the actuator unit A2 operate are described as follows: [Table 1]

[0041] When the leg 71 extends to the extension amount L1, the actuator unit A1 operates and an ON signal S1 is sent to the control device 3. When the leg 71 further extends to the extension amount L2, the actuator unit A2 operates and an ON signal S2 is sent to the control device 3.

[0042] A touch panel 8, which is an example of an input device and a display device, is connected to the control device 3. In this embodiment, the control device 3 determines whether the installation height of the heater 60 is higher than the reference height.

[0043] As described in the first embodiment, the reference height H is the maximum height that the flammable liquid contained in the contents of the tank 20 can reach from the floor of the explosion-proof area when the flammable liquid vaporizes and becomes a flammable gas heavier than air and is released into the explosion-proof area. The reference height H is calculated based on the amount of flammable liquid contained in the contents of the tank 20 brought into the explosion-proof area and the floor area of ​​the explosion-proof area. It may be estimated assuming that the maximum amount of flammable liquid in the tank 20 will evaporate entirely, or that only a portion of the flammable liquid will evaporate. If the reference height H is significantly affected by the air pressure and temperature of the explosion-proof area, the reference height H may be calculated based on the air pressure and temperature in addition to the amount of flammable liquid and floor area. Alternatively, the reference height H may be calculated based on the amount of flammable liquid and floor area assuming normal temperature and normal pressure.

[0044] 5, such a reference height is stored in advance in the memory of the control device 3. Alternatively, the amount of flammable liquid, floor area, temperature, and pressure that affect the calculation of the reference height may be input via the touch panel 8, and the control device 3 may calculate the reference height based on these values.

[0045] The height of the heater 60 relative to the floor of the explosion-proof area when the legs 71 are at the standard length is stored in the storage unit of the control device 3. This height is set as the initial installation height M0 of the heater 60.

[0046] The control device 3 includes an installation height calculation unit that calculates the installation height, a determination unit based on the installation height and the reference height, and a heating control unit that controls heating of the heater 60 based on the result of the determination unit. Each of these units is part of a program executed by the control device 3.

[0047] First, the installation height calculation unit obtains the extension amount L of the leg 71 based on the ON signal received from the limit switch device 80. For example, if the ON signal S1 is received, the extension amount L1 is read from the storage unit. Similarly, if the ON signal S2 is received, the extension amount L2 is read from the storage unit.

[0048] The installation height calculation unit calculates the installation height M based on the extension amount L1 or extension amount L2 obtained as described above and the initial installation height M0. If the extension amount L of the leg 71 is extension amount L1, the installation height M is M0+L1. If the extension amount L of the leg 71 is extension amount L2, the installation height M is M0+L2.

[0049] The determination unit compares the installation height M obtained as described above with the reference height H stored in the memory unit, and determines whether the installation height M is higher than the reference height H. This determination result is displayed, for example, on the touch panel 8. This makes it possible to inform the worker that even if an electrical malfunction occurs in the heater 60 and it becomes a source of ignition, there is no risk of ignition of the flammable gas because the heater 60 is installed at a position higher than the reference height H.

[0050] The heating control unit heats the heat medium with the heater 60 only when it determines that the installation height M of the heater 60 is higher than the reference height H. In other words, the heating control unit realizes an interlock function. For example, the control device 3 is configured to display an input screen for controlling heating with the heater 60 on the touch panel 8, and to cause the heating control unit to perform heating with the heater 60 in response to an input operation on the touch panel 8. In this case, the heating control unit causes heating with the heater 60 only when it determines that the installation height M is higher than the reference height H. As a result, even if heating with the heater 60 is instructed when the installation height M is lower than the reference height H, heating is not actually performed, thereby more reliably preventing ignition of flammable gas.

[0051] The operation of the tank system 1 for use in an explosion-proof area will be described using Figures 6 to 8. Figure 6 is a schematic diagram of the tank system 1 for use in an explosion-proof area when the legs 71 are at the standard length. Figure 7 is a schematic diagram of the tank system 1 for use in an explosion-proof area when the legs 71 are extended by an extension amount L2. Figure 8 is an example of a display on the touch panel 8.

[0052] 6, the legs 71 are not extended by the adjusters 74, that is, are at the reference length. In this state, the heater 60 fixed to the actual tank 20 is located at a position lower than the reference height H.

[0053] In this state, the installation height calculation unit of the control device 3 determines that the initial installation height M0 is the installation height M, and the determination unit determines that the installation height M is smaller than the reference height H. Note that the initial installation height M0 is the height from the floor to the lowest part of the heater 60. As shown in FIG. 8(a), the control device 3 displays the installation height M and the reference height H on the touch panel 8, and makes the "Start Heating" button unpressable, or even if it can be pressed, the heater 60 does not actually heat. The control device 3 then displays a message that heating by the heater 60 is not possible.

[0054] As shown in Figure 7, the leg 71 is extended by the adjuster 74, activating the actuator A2, i.e., extended by an amount L2. In this state, the heater 60 fixed to the actual tank 20 is located higher than the reference height H. In this state, the control device 3 operates as follows.

[0055] The installation height calculation unit of the control device 3 receives the on signal S2 and obtains the corresponding extension amount L2 from the memory unit. It also obtains the initial installation height M0 from the memory unit. The sum of the initial installation height M0 and the extension amount L2 is set to the installation height M. The determination unit determines that the installation height M is greater than the reference height H. As shown in Figure 8(b), the control device 3 displays the installation height M and reference height H on the touch panel 8 and makes the "Start heating" button pressable, and when pressed, actually starts heating with the heater 60. The control device 3 then displays a message that heating with the heater 60 is possible.

[0056] The tank system 1 for an explosion-proof area of ​​the second embodiment described above includes legs 71 with adjusters 74, which are adjustment means for adjusting the installation height M of the heater 60 in the height direction relative to the floor of the explosion-proof area. The control device 3 includes a determination unit that determines whether the installation height M obtained from the detection means is higher than the reference height stored in the memory unit.

[0057] According to the tank system 1 for explosion-proof areas configured as described above, the installation height M of the heater 60 can be adjusted to a position higher than the reference height H, and the control device 3 can determine this. This allows the tank 20 containing a liquid content that may generate flammable gas to be safely heated by the heater 60.

[0058] The reference height is the maximum height that the flammable liquid contained in the contents of the tank vaporizes and turns into flammable gas that is heavier than air, and that the flammable gas is released into the explosion-proof area 2 and can reach from the floor of the explosion-proof area 2. The reference height is calculated based on the amount of flammable liquid contained in the contents of the tank 20 that is brought into the explosion-proof area 2 and the floor area of ​​the explosion-proof area 2. By basing the reference height on the amount of flammable liquid and the floor area, it is possible to obtain a more accurate reference height.

[0059] In the tank system 1 for an explosion-proof area of ​​the second embodiment, the control device 3 heats the heat medium with the heater 60 only when it determines that the installation height M is higher than the reference height H. Because such an interlock function is realized, it is possible to prevent the heater 60 from heating when the heater 60 is located at a position lower than the reference height.

[0060] By extending the legs 71 with the adjusters 74, the installation height M of the heater fixed to the tank 20 can be adjusted, and it can be easily moved to a position higher than the reference height H.

[0061] The legs 71 with the adjusters 74 are an example of a "support member that supports a tank and is extendable and contractible in the height direction" as claimed in the claims. Of course, the support member is not limited to this example. For example, the support member may be configured such that an air cylinder or hydraulic cylinder that moves a piston rod back and forth is incorporated as part of the legs. Furthermore, the support member may not directly support the tank, but may indirectly support the tank via a moving means 70 that supports the tank 20. For example, an adjuster or the like may be attached to the moving means 70 in FIG. 3, and the moving means 70 may be moved in the height direction of the tank 20 as the adjuster extends and contracts in the height direction.

[0062] The detection means for detecting the installation height includes a limit switch device 80 and an installation height calculation unit. The limit switch device 80 detects the extent to which the legs 71 are extended, and the installation height calculation unit calculates the installation height based on the detection result. This makes it possible to obtain the installation height automatically and more accurately.

[0063] The limit switch device 80 is an example of a first detection device as defined in the claims. Of course, the first detection device is not limited to this example. For example, a known proximity sensor can be used as the first detection device. Proximity sensors include those that use eddy currents generated in a metal object to be detected by electromagnetic induction, those that detect changes in electrical capacitance due to the proximity of a detected object, and those that use magnets or reed switches. When a portion of the leg 71 reaches the detection range of the proximity sensor, the proximity sensor transmits a signal to the control device 3. Upon receiving the signal, the control device 3 reads the extension corresponding to the signal from a memory unit and calculates the installation height, as in the above embodiment. Alternatively, a camera capturing an image of the leg 71 may be used as the first detection device. The control device 3 may calculate the extension by processing the image captured by the camera and then calculate the installation height based on the extension. In this case, the camera and the image processing function serve as the detection means.

[0064] A touch panel 8 is provided that displays the determination result by the control device 3 as shown in Fig. 8. This allows the worker to confirm whether the heater 60 is in a safe position.

[0065] Third Embodiment A tank system 1 for an explosion-proof area according to embodiment 3 will be described with reference to Figure 9. The tank system 1 for an explosion-proof area according to embodiment 3 differs from embodiment 2 in the means for detecting the installation height of the heater 60. Note that the same components as those in embodiments 1 and 2 are given the same reference numerals, and redundant explanations will be omitted.

[0066] As shown in Figure 9, a distance measuring device 90 is attached to the tank 20. The distance measuring device 90 is a device that can measure the distance from the installation position of the distance measuring device 90 to an object by, for example, emitting laser light and capturing the light reflected from the floor of the explosion-proof area 2. The height (distance) from the floor of the explosion-proof area 2 to the installation position measured by the distance measuring device 90 is defined as the installation height N1. The distance measuring device 90 and the control device 3 can communicate wirelessly or via a cable, and the installation height N1 detected by the distance measuring device 90 is transmitted to the control device 3.

[0067] The memory unit of the control device 3 stores the distance N0 in the height direction between the distance measuring device 90 and the heater 60. The installation height calculation unit of the control device 3 calculates the installation height M based on the installation height N1 detected by the distance measuring device 90. Specifically, the installation height M is the sum of the installation height N1 and the distance N0 read from the memory unit.

[0068] When the length of the leg 71 is increased by extending the adjuster 74, the tank 20 also moves upward. The installation height calculation unit of the control device 3 updates the installation height M based on the mounting height N1 after the distance measuring device 90 has moved and the distance N0. Thereafter, as in the second embodiment, the installation height M is compared with the reference height H, and whether or not the heater 60 should heat is determined based on the result of the determination.

[0069] In this manner, in this embodiment, the installation height M can be obtained based on the mounting height N1 obtained by the distance measuring device 90 attached to the tank 20. In a configuration such as the second embodiment where it is difficult to detect the extension of the legs 71, it is effective to use the distance measuring device 90.

[0070] The distance measuring device 90 is an example of a second detecting device as claimed in the claims. The distance measuring device 90 and the installation height calculation unit are an example of a detecting means.

[0071] Fourth Embodiment In the first to third embodiments, the tank system 1 for an explosion-proof area is illustrated as using the same type of tank apparatus 10, but is not limited to such a configuration. A different type of tank apparatus 10 having a different installation height range of the heater 60 may also be used.

[0072] In the tank device 10 of the second and third embodiments, the installation height M of the heater 60 fixed to the tank 20 in the height direction can be adjusted by extending and contracting the legs 71 using the adjuster 74. The installation height M of the heater 60 falls within a certain range depending on the amount of extension and contraction of the legs 71.

[0073] "The ranges of the installation height M are different" means that the ranges do not completely overlap. If the ranges of the installation height M are different, the tank devices 10 are considered to be of different types. For example, suppose there are two different types of tank devices 10, a large tank device 10A and a small tank device 10B, each with a different range of the installation height M.

[0074] An information processing device such as a personal computer is prepared, and the information processing device is configured so that the range of installation height M and reference height H of each tank device 10 can be input. The information processing device compares the installation height M of each tank device with the reference height H, and selects a tank device 10 having an installation height M higher than the reference height H. [Table 2]

[0075] For example, as shown in Table 2, if the range of the installation height M of the large tank device 10A is "1000-1500" [mm] and the installation height H is 1200 [mm], the judgment unit will judge that the installation height M is greater than the reference height H of 1200 [mm]. In other words, if the reference height H is included within the range of the installation height H, the installation height M of the heater 60 will be judged to be higher than the reference height H.

[0076] On the other hand, if the range of the installation height M of the small tank device 10B is "800-1100" [mm], the judgment unit judges that the installation height M is smaller than the reference height H of 1200 [mm]. In other words, if the reference height H is smaller than the lower limit of the range of the installation height H, the judgment unit judges that the installation height M of the heater 60 is lower than the reference height H.

[0077] In this way, the information processing device selects a tank device 10 for which the installation height M of the heater 60 is determined to be higher than the reference height H, and displays on a display device such as a display that it is recommended that the tank device 10 be used in the explosion-proof area 2.

[0078] In this way, it is possible to present to the worker the tank device 10 that is suitable for use in the explosion-proof area 2. The information processing device is an example of the recommendation means recited in the claims. [Explanation of symbols]

[0079] H...Base height, 1...Tank system, 2...Explosion-proof area, 3...Control device, 4...Power supply, 5...Air supply device, 6...Power cable, 7...Piping, 10...Tank device, 20...Tank, 30...Jacket, 40...Circulation flow path, 50...Pump, 60...Heater, 70...Transportation means

Claims

1. A tank system for an explosion-proof area including a tank device to be installed in an explosion-proof area and a control device, The tank device A tank installed in an explosion-proof area; a jacket provided on the outer periphery of the tank and through which a heat transfer medium flows; an electric heater that heats the heat medium in the jacket; an adjustment means for adjusting the installation height of the electric heater in a height direction relative to the floor of the explosion-proof area; a detection means for detecting the installation height, The control device includes a determination unit that determines whether the installation height obtained from the detection means is higher than a reference height stored in a storage unit. A tank system for explosion-proof areas characterized by:

2. 2. The tank system for an explosion-proof area according to claim 1, The reference height is The flammable liquid contained in the content liquid of the tank vaporizes to become a flammable gas heavier than air, and the flammable gas released into the explosion-proof area is the maximum height that can reach from the floor of the explosion-proof area, The calculation is based on the amount of flammable liquid contained in the contents of the tank brought into the explosion-proof area and the floor area of ​​the explosion-proof area. A tank system for explosion-proof areas characterized by:

3. 2. The tank system for an explosion-proof area according to claim 1, The control device heats the heat medium with the electric heater only when it determines that the installation height is higher than the reference height. A tank system for explosion-proof areas characterized by:

4. 2. The tank system for an explosion-proof area according to claim 1, The electric heater is fixed to the tank, The adjustment means is a support member that supports the tank and is extendable in the height direction. A tank system for explosion-proof areas characterized by:

5. 5. The tank system for an explosion-proof area according to claim 4, The support member is extendable in a height direction from a reference length, The detection means a first detector for detecting an extension of the length of the support member; an installation height calculation unit provided in the control device that calculates the installation height; The installation height calculation unit calculates the installation height based on an initial installation height of the electric heater in a height direction relative to a floor of the explosion-proof area when the support member has a standard length and an extension detected by the first detection device. A tank system for explosion-proof areas characterized by:

6. 2. The tank system for an explosion-proof area according to claim 1, The detection means a second detection device fixed to the tank, the second detection device detecting a height between a mounting position of the second detection device and a floor of the explosion-proof area; an installation height calculation unit provided in the control device that calculates the installation height; The installation height calculation unit calculates the installation height based on the height detected by the second detection device. A tank system for explosion-proof areas characterized by:

7. 2. The tank system for an explosion-proof area according to claim 1, The tank device is provided with a display device that displays the installation height, the reference height, and the result of the determination by the control device. A tank system for explosion-proof areas characterized by:

8. 2. The tank system for an explosion-proof area according to claim 1, A plurality of the tank devices having different installation height ranges are provided, a recommendation unit for recommending the tank device having an installation height higher than the reference height; A tank system for explosion-proof areas characterized by:

9. 2. The tank system for an explosion-proof area according to claim 1, The tank device an air-driven pump that pumps the heat medium; a circulation flow path that circulates the heat medium between the jacket and the air-driven pump, an air supply device for supplying air for operating the air-driven pump is installed in the explosion-proof area; The air-driven pump is provided at a position lower than the reference height. A tank system for explosion-proof areas characterized by:

10. 2. The tank system for an explosion-proof area according to claim 1, a moving means for supporting the tank and for moving the tank; A tank system for explosion-proof areas characterized by:

Images